Unit for refrigeration cycle device, refrigeration cycle device, and electric apparatus

ABSTRACT

A unit for a refrigeration cycle device includes a housing that internally includes a sound field space surrounded by surfaces each reflecting sound waves, an expansion device disposed in the sound field space and configured to adjust a flow rate of refrigerant, a refrigerant pipe disposed in the sound field space and connected to the expansion device, and a sound absorber disposed on at least a part of the surfaces defining the sound field space.

TECHNICAL FIELD

The present disclosure relates to a unit for a refrigeration cycledevice that includes a space in which an expansion device and arefrigerant pipe connected to the expansion device are accommodated, arefrigeration cycle device including the unit for a refrigeration cycledevice, and an electric apparatus including the refrigeration cycledevice.

BACKGROUND ART

An expansion device that is one component of a refrigeration cycledevice is commonly mounted together with a refrigerant pipe connected tothe expansion device, on a unit for a refrigeration cycle device such asa heat source side unit and a use side unit. Accordingly, the unit for arefrigeration cycle device includes a space in which the expansiondevice and the refrigerant pipe connected to the expansion device areaccommodated. The space is unsealed and open.

In the refrigeration cycle device, refrigerant inside the refrigerantpipe makes a transition to any of three states of a gas phase state, aliquid phase state, and a two-phase gas-liquid state depending on anoperation state. Further, different refrigerant noise is generated ineach of the phase states of the refrigerant. In any of the phase states,the refrigerant noise is generated in particular when the refrigerantpasses through an electronic expansion valve that is the expansiondevice. In the following, the electronic expansion valve is referred toas a LEV.

More specifically, a fluid vibration phenomenon different from avibration phenomenon caused by a flow of the refrigerant and noisecaused by the fluid vibration phenomenon occur because of collision ofthe refrigerant with a wall surface inside the LEV and disturbance ofthe flow of the refrigerant at a corner of a valve body that is a partof components of the LEV. Further, standing waves generated in astructure space inside the LEV and in a structure space inside therefrigerant pipe, the flow of the refrigerant itself, a turbulentcomponent caused by disturbance of the refrigerant flow, and sound wavesderived from excited noise caused by collision inside the LEV and insidethe refrigerant pipe are combined to cause large noise.

For such a reason, for example, in Patent Literature 1, a resonancespace is provided close to the LEV to reduce the refrigerant noiseinside the refrigerant pipe. According to Patent Literature 1, it ispossible to adjust a position of an antinode of a resonance mode. Thisadjustment makes it possible to lower an amplitude level of theresonance sound and to reduce noise. In other words, in PatentLiterature 1, the refrigerant noise is amplified by resonance in aninternal space of the LEV when the refrigerant passes through the LEV,and a resonance adjuster that includes a resonance space as measuresagainst the amplification of the refrigerant noise is provided to theLEV.

Further, in some technology, a rubber vibration insulator is attached tothe refrigerant pipe connected to the LEV, to take measures againstvibration.

In Patent Literature 2, a shape of an opening port through which therefrigerant flows, inside the LEV is devised to effectively disperse theflow of the refrigerant. This dispersion reduces fluid energy to reducethe refrigerant noise.

Further, in Patent Literature 3, to prevent noise from an expansionmechanism such as a LEV, a strainer, and a silencer from radiating tooutside of a product, the expansion mechanism is covered with a soundreducing plate.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent No. 4079177

Patent Literature 2: Japanese Patent No. 5881845

Patent Literature 3: Japanese Unexamined Patent Application PublicationNo. 9-280597

SUMMARY OF INVENTION Technical Problem

In the technology disclosed in Patent Literature 1, the refrigerantnoise cannot be reduced by the measures against vibration as therefrigerant noise involves acoustic radiation by transmitted noisephenomenon from the inside of the refrigerant pipe caused by acoincidence phenomenon of the refrigerant pipe. The coincidencephenomenon is a phenomenon in which, when a sound wave of a certainfrequency enters a rigid material, flexural vibration of the rigidmaterial and vibration of the sound wave that enter are coincident witheach other to cause a resonance state.

The measures against the refrigerant noise by the structure disclosed inPatent Literature 2 or Patent Literature 3 achieve the reduction effectto the vibration noise and the refrigerant noise caused by the structurebut cannot achieve the reduction effect of the sound pressure level toall of the refrigerant noise generated depending on a flow rate of therefrigerant varying with time.

Further, as the types of the refrigerant noise, there are vibrationnoise propagating through the inside of the refrigerant pipe and thenoise by space resonance including compressional waves of the noise at aconstant period, in addition to the noise caused by flow of therefrigerant inside the refrigerant pipe. In addition, these noises areamplified at some positions. For the reasons, it is difficult to reduceall of the refrigerant noise phenomenon only by the structure of therefrigerant pipe or the resonance pipe connected to the LEV. Further, inaddition to the vibration, it is difficult to cope with the transmittednoise transmitted from the refrigerant pipe to the outside.

The present disclosure is made in consideration of the above-describedissues, and relates to a unit for a refrigeration cycle device, arefrigeration cycle device, and an electric apparatus that each make itpossible to prevent vibration noise radiated from a refrigerant pipe,transmitted noise transmitted from the inside to the outside of therefrigerant pipe, and other sound from leaking as noise to the outside.

Solution to Problem

A unit for a refrigeration cycle device according to an embodiment ofthe present disclosure includes a housing that internally includes asound field space surrounded by surfaces each reflecting sound waves, anexpansion device disposed in the sound field space and configured toadjust a flow rate of refrigerant, a refrigerant pipe disposed in thesound field space and connected to the expansion device, and a soundabsorber disposed on at least a part of the surfaces defining the soundfield space.

Advantageous Effects of Invention

In the unit for a refrigeration cycle device according to an embodimentof the present disclosure, the sound absorber is disposed on at least apart of the surfaces defining the sound field space. Therefore, thestanding wave component in the sound field space are reduced, and it isthus possible to prevent noise from leaking to the outside of the soundfield space.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram to explain frequency characteristics ofrefrigerant noise generated from a refrigeration cycle device.

FIG. 2 is a schematic configuration diagram illustrating an exemplaryconfiguration of a refrigerant circuit of a refrigeration cycle deviceaccording to an embodiment of the present disclosure.

FIG. 3 is a schematic configuration diagram schematically illustratingan internal configuration example of a load side unit as viewed from afront, according to the embodiment of the present disclosure.

FIG. 4 is a schematic cross-sectional view schematically illustrating across-section taken along line A-A in FIG. 3.

FIG. 5 is an explanatory diagram to explain “standing waves” present inan acoustic space.

FIG. 6 is an explanatory diagram to explain “standing waves in verticaldirection” present in an acoustic space defined in a housing of a commonload side unit.

FIG. 7 is an explanatory diagram to explain “standing waves infront-rear direction” present in the acoustic space defined in thehousing of the common load side unit.

FIG. 8 is an explanatory diagram to explain “standing waves inright-left direction” present in the acoustic space defined in thehousing of the common load side unit.

FIG. 9 is a schematic cross-sectional view schematically illustrating aconfiguration example of a load side unit that includes a sound absorberat an upper part of a first space, as viewed from a side.

FIG. 10 is a schematic cross-sectional view schematically illustrating aconfiguration example of a load side unit that includes a sound absorberat a rear surface part of a first space, as viewed from a side.

FIG. 11 is a schematic configuration diagram schematically illustratinga configuration example of a load side unit that includes a soundabsorber at a side surface part of a first space, as viewed from afront.

FIG. 12 is a schematic configuration diagram schematically illustratinga state where the configuration examples of FIG. 9 to FIG. 12 arecombined.

FIG. 13 is a schematic layout diagram schematically illustrating alayout example of a refrigerant pipe inside a housing of the load sideunit according to the embodiment of the present disclosure.

FIG. 14 is a schematic configuration diagram schematically illustratinga modification of the load side unit according to the embodiment of thepresent disclosure.

FIG. 15 is an explanatory diagram to explain action in a case where asound insulator is stacked on a sound absorber and the stacked body isdisposed on the refrigerant pipe.

FIG. 16 is a schematic cross-sectional view schematically illustrating across-sectional configuration in the case where the sound insulator isstacked on the sound absorber and the stacked body is disposed on therefrigerant pipe.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present disclosure is described below withreference to drawings. Note that, in the following drawings includingFIG. 1, size relationship of components may be different from actualsize relationship. Further, in the following drawings including FIG. 1,components denoted by the same reference signs are the same orequivalent components, and the reference signs are common in the fulltext of the specification. Furthermore, forms of the componentsdescribed in the full text of the specification are merely illustrative,and are not limited to the described forms.

First, frequency characteristics of refrigerant noise generated from arefrigeration cycle device are described. FIG. 1 is an explanatorydiagram to explain the frequency characteristics of the refrigerantnoise generated from the refrigeration cycle device. Refrigerant flownoise generated from the refrigeration cycle device is described withreference to FIG. 1.

Note that FIG. 1 illustrates, as a graph, an example of the frequencycharacteristics of the refrigerant noise generated from therefrigeration cycle device commonly used. Further, in FIG. 1, a verticalaxis represents a sound pressure level (dB), and a horizontal axisrepresents a frequency (kHz).

In the refrigeration cycle device, refrigerant inside a refrigerantcircuit makes a transition to any of three states of a gas phase state,a two-phase gas-liquid state, and a liquid phase state depending on anoperation condition of the refrigeration cycle device. Under the phaseconditions, different refrigerant noise is generated. In particular,when the refrigerant passes through the LEV, a fluid vibrationphenomenon different from a vibration phenomenon caused by a flow of therefrigerant and noise caused by the fluid vibration phenomenon occurbecause of collision of the refrigerant with a wall surface inside theLEV and disturbance of the flow of the refrigerant at a corner of avalve body that is a part of components of the LEV.

Furthermore, standing waves generated in a structure space inside theLEV and in a structure space inside a refrigerant pipe, the flow of therefrigerant itself, a turbulent component caused by disturbance of therefrigerant flow, and sound waves derived from excited noise caused bycollision inside the LEV and inside the refrigerant pipe are combined tocause large noise.

As illustrated by a line A in FIG. 1, for example, in a case where therefrigerant is in the liquid phase state, a plurality of peak componentsare generated in a band that ranges from about 1 kHz to 3 kHz. Further,as illustrated by a line B in FIG. 1, in a case where the refrigerant isin the gas phase state, a plurality of peak components are generated ina band of 5 kHz to 7 kHz. Further, as illustrated by a line C in FIG. 1,in a case where the refrigerant is in the two-phase gas-liquid state, aplurality of peak components are generated in a band of 3 kHz to 5 kHzand in an ultrasonic band of 10 kHz or more. In the case where therefrigerant is in the gas phase or in the liquid phase, theabove-described peak component is generated as a single peak componentin some cases.

In a case where the plurality of peak components are generated,differential noise caused by fluctuation phenomenon and the refrigerantnoise that has “chordal” sound quality influenced by the plurality ofpeak components are also generated. The refrigerant noise caused by sucha phenomenon is generated during operation of the refrigeration cycledevice. Therefore, even at bedtime at night, the refrigerant noise isgenerated from an indoor unit installed in an air-conditioned space.This noise gives discomfort to a person sleeping in the air-conditionedspace. In the case where the refrigerant is in the two-phase gas-liquidstate, the variable refrigerant noise particularly giving discomfort isgenerated.

The gas-phase component in the two-phase gas-liquid state can berepresented as aggregates of bubbles having various dimensionaldiameters. Further, the bubbles each having an extremely small bubblediameter are micro-class bubbles and can be referred to as microbubbles.Further, pressure inside the refrigerant pipe included in therefrigerant circuit is high to circulate the refrigerant, andacceleration is applied to the refrigerant. When the micro-class bubblesare generated in the refrigerant in the two-phase gas-liquid stateflowing at high speed, the bubbles travel in the refrigerant pipes whilethe bubbles are accelerated by pressure. At this time, the air issquashed inside each of the bubbles.

Such bubbles in the high-pressure state flow into the LEV, collide withthe components such as a valve body of the LEV, and are burst. At thistime, a cavitation phenomenon occurs, and “sound=noise” called bubblepulse is generated by bubble burst. The noise, namely, the cavitationnoise has acoustic characteristics that generate a plurality of peakcomponents in a high frequency band through an ultrasonic band of thefrequency higher than or equal to 10 kHz, as illustrated in FIG. 1.

The noise of the ultrasonic band repeatedly varies depending ondiameters of the bubbles, collision of the bubbles, and a passage stateof the bubbles, and various frequencies are generated. The frequenciesare generated as pipe vibration, and the vibration propagates astransmitted noise to the outside of the refrigerant pipe. Thetransmitted noise that has propagated to the outside of the refrigerantpipe reaches a person as unpleasant noise of the audible band. In otherwords, the adjacent frequencies of a plurality of ultrasonic waves inthe peak state are generated. The peak components of the ultrasonic bandare sound waves of a nonlinear region, and are generated as frequencycomponents of difference and summation by a well-known parametricphenomenon between the adjacent frequencies.

Further, the plurality of peak components in the ultrasonic bandgenerate the fluctuation phenomenon, and generate differential noise.The frequency components of the differential noise are generated in theaudible frequency band. Therefore, the differential noise is generatedfrom the LEV and the refrigerant pipe connected to the LEV. Thedifferential noise is radiated as sound (noise), and is provided asunpleasant noise to, for example, a sleeping person.

FIG. 2 is a schematic configuration diagram illustrating an exemplaryconfiguration of a refrigerant circuit of a refrigeration cycle device100 according to the embodiment of the present disclosure.

FIG. 2 illustrates, as an example, a case where the refrigeration cycledevice 100 is mounted on an air-conditioning apparatus that is anexample of an electric apparatus. Further, in FIG. 2, a flow of therefrigerant during cooling operation is illustrated by solid arrows, anda flow of the refrigerant during heating operation is illustrated bydashed arrows.

<Configuration of Refrigeration Cycle Device 100>

As illustrated in FIG. 2, the refrigeration cycle device 100 includes arefrigerant circuit in which a compressor 1, a flow switching device 2,a first heat exchanger 3, a LEV 50, and a second heat exchanger 5 areconnected by a refrigerant pipe 15.

FIG. 2 illustrates, as an example, the refrigeration cycle device 100that includes the flow switching device 2 and can switch the coolingoperation and the heating operation by the flow switching device 2;however, the flow switching device 2 may not be provided and the flowdirection of the refrigerant may be fixed.

The compressor 1, the flow switching device 2, and the first heatexchanger 3 are mounted on a heat source side unit 100B. The heat sourceside unit 100B is one of units for a refrigeration cycle device. Theheat source side unit 100B is installed in a space different from anair-conditioned space, for example, outdoor, and is configured to supplycooling energy or heating energy to a load side unit 100A. Note that theheat source side unit 100B is also referred to as an outdoor unit.

The second heat exchanger 5 and the LEV 50 are mounted on the load sideunit 100A. The load side unit 100A is one of the units for arefrigeration cycle device. The load side unit 100A is installed in aspace to supply the cooling energy or the heating energy to theair-conditioned space such as a living space, and is configured to coolor heat the air-conditioned space by the cooling energy or the heatingenergy supplied from the heat source side unit 100B. Note that the loadside unit 100A is also referred to as a use side unit or an indoor unit.

The compressor 1 compresses the refrigerant and discharges thecompressed refrigerant. Examples of the compressor 1 include a rotarycompressor, a scroll compressor, a screw compressor, and a reciprocatingcompressor. In a case where the first heat exchanger 3 is used as acondenser, the refrigerant discharged from the compressor 1 is fed tothe first heat exchanger 3 through the refrigerant pipe 15. In a casewhere the first heat exchanger 3 is used as an evaporator, therefrigerant discharged from the compressor 1 is fed to the second heatexchanger 5 through the refrigerant pipe 15.

The flow switching device 2 is provided to a discharge port of thecompressor 1, and switches the flows of the refrigerant between theheating operation and the cooling operation. Examples of the flowswitching device 2 include a four-way valve and a combination of anyones of three-way valves and two-way valves.

The first heat exchanger 3 is used as an evaporator during the heatingoperation, and is used as a condenser during the cooling operation.Examples of the first heat exchanger 3 include a fin-and-tube heatexchanger.

The first heat exchanger 3 is provided with a first air-sending device6. The first air-sending device 6 supplies air as heat exchanging fluidto the first heat exchanger 3. Examples of the first air-sending device6 include a propeller fan including a plurality of blades.

The LEV 50 is an electronic expansion valve that is an example of theexpansion device, and decompresses the refrigerant that has passedthrough the second heat exchanger 5 or the first heat exchanger 3. Thecase where the LEV 50 is mounted on the load side unit 100A is describedhere as an example; however, the LEV 50 may be mounted on the heatsource side unit 100B. Further, the LEV 50 is described as an example ofthe expansion device; however, the expansion device is not limited tothe LEV 50, and the type of the expansion device is not particularlylimited as long as the expansion device includes a valve body thatadjusts a flow rate of the refrigerant.

The second heat exchanger 5 is used as a condenser during the heatingoperation, and is used as an evaporator during the cooling operation.Examples of the second heat exchanger 5 include a fin-and-tube heatexchanger.

The second heat exchanger 5 is provided with a second air-sending device7. The second air-sending device 7 supplies air as heat exchanging fluidto the second heat exchanger 5. Examples of the second air-sendingdevice 7 include a propeller fan including a plurality of blades.

<Operation of Refrigeration Cycle Device 100>

Next, operation of the refrigeration cycle device is described togetherwith the flow of the refrigerant. The operation of the refrigerationcycle device 100 in a case where the heat exchanging fluid is air andheat exchanged fluid is the refrigerant is described as an example.

First, the cooling operation performed by the refrigeration cycle device100 is described.

When the compressor 1 is driven, the refrigerant in a high-temperaturehigh-pressure gas state is discharged from the compressor 1.Subsequently, the refrigerant flows as illustrated by solid arrows. Thehigh-temperature high-pressure gas refrigerant discharged from thecompressor 1 flows into the first heat exchanger 3, which is used as acondenser, through the flow switching device 2. In the first heatexchanger 3, heat is exchanged between the flowing-in high-temperaturehigh-pressure gas refrigerant and the air supplied from the firstair-sending device 6, and the high-temperature high-pressure gasrefrigerant is condensed into high-pressure liquid refrigerant.

The high-pressure liquid refrigerant fed out from the first heatexchanger 3 becomes refrigerant in a two-phase gas-liquid statecontaining low-pressure gas refrigerant and low-pressure liquidrefrigerant through the LEV 50. The two-phase gas-liquid refrigerantflows into the second heat exchanger 5, which is used as an evaporator.In the second heat exchanger 5, heat is exchanged between the flowing-intwo-phase gas-liquid refrigerant and the air supplied from the secondair-sending device 7, and the liquid refrigerant of the two-phasegas-liquid refrigerant is evaporated into low-pressure gas refrigerant.The air-conditioned space is cooled by the heat exchange. Thelow-pressure gas refrigerant fed out from the second heat exchanger 5flows into the compressor 1 through the flow switching device 2, and iscompressed into the high-temperature high-pressure gas refrigerant. Thehigh-temperature high-pressure gas refrigerant is again discharged fromthe compressor 1. Subsequently, this cycle is repeated.

Next, the heating operation performed by the refrigeration cycle device100 is described.

When the compressor 1 is driven, the refrigerant in the high-temperaturehigh-pressure gas state is discharged from the compressor 1.Subsequently, the refrigerant flows as illustrated by dashed arrows. Thehigh-temperature high-pressure gas refrigerant discharged from thecompressor 1 flows into the second heat exchanger 5, which is used as acondenser, through the flow switching device 2. In the second heatexchanger 5, heat is exchanged between the flowing-in high-temperaturehigh-pressure gas refrigerant and the air supplied from the secondair-sending device 7, and the high-temperature high-pressure gasrefrigerant is condensed into high-pressure liquid refrigerant. Theair-conditioned space is heated by the heat exchange.

The high-pressure liquid refrigerant fed out from the second heatexchanger 5 becomes refrigerant in a two-phase gas-liquid statecontaining low-pressure gas refrigerant and low-pressure liquidrefrigerant through the LEV 50. The two-phase gas-liquid refrigerantflows into the first heat exchanger 3, which is used as an evaporator.In the first heat exchanger 3, heat is exchanged between the flowing-intwo-phase gas-liquid refrigerant and the air supplied from the firstair-sending device 6, and the liquid refrigerant of the two-phasegas-liquid refrigerant is evaporated into low-pressure gas refrigerant.The low-pressure gas refrigerant fed out from the first heat exchanger 3flows into the compressor 1 through the flow switching device 2, and iscompressed into the high-temperature high-pressure gas refrigerant. Thehigh-temperature high-pressure gas refrigerant is again discharged fromthe compressor 1. Subsequently, this cycle is repeated.

<Configuration of Load Side Unit 100A>

FIG. 3 is a schematic configuration diagram schematically illustratingan internal configuration example of the load side unit 100A as viewedfrom a front. FIG. 4 is a schematic cross-sectional view schematicallyillustrating a cross-section taken along line A-A in FIG. 3. Theinternal configuration of the load side unit 100A, which is one of theunits for a refrigeration cycle device according to the embodiment ofthe present disclosure, is described with reference to FIG. 3 and FIG.4. Note that FIG. 3 illustrates an inside of the load side unit 100Awith a front panel 77 removed from the load side unit 100A. Further,FIG. 3 illustrates a state viewed through a drain cover 33 in such amanner that the LEV 50 and the refrigerant pipe 15 are visuallyrecognizable.

The load side unit 100A includes a housing 70 that forms an outer shell.A front surface of the housing 70 includes the front panel 77, which isattached in such a manner that the front panel 77 may be detached. Thefront panel 77 is used as a design cover of the load side unit 100A. Atop surface of the housing 70 includes a top panel 71 through which anopening port 71 a used as an air inlet penetrates. The top panel 71 isused as the design cover of the load side unit 100A, together with thefront panel 77. A rear surface of the housing 70 includes a base 76 tobe attached to, for example, a wall of the air-conditioned space. Sidesurfaces of the housing 70 each include a side panel. A bottom surfaceof the housing 70 includes a bottom panel 78 through which an air outlet80 penetrates.

Note that a case where the load side unit 100A is of a wall mounted typeis described as an example; however, the type is not limited to a wallmounted type, and the load side unit 100A may be of a ceiling concealedtype, a ceiling suspended type, or a floor mounted type. In a case wherethe load side unit 100A is not of the wall mounted type, the rearsurface of the housing 70 includes a rear panel.

Further, the side panels may be each a detachable panel separated fromthe top panel 71 and the bottom panel 78, or may be integrated with thetop panel 71 and the bottom panel 78.

Further, a wind direction adjusting unit 81 that adjusts a direction ofthe air blown out from the air outlet 80 in vertical and rightdirections is disposed at the air outlet 80.

As illustrated in FIG. 3 and FIG. 4, an inside of the housing 70 ispartitioned by a first partition plate 30 and a second partition plate31. In the internal space of the housing 70 partitioned by the firstpartition plate 30 and the second partition plate 31, a space in whichthe second heat exchanger 5, the LEV 50, and the refrigerant pipe 15 areaccommodated is referred to as a first space 35. Further, in theinternal space of the housing 70 partitioned by the first partitionplate 30 and the second partition plate 31, a space in which acontroller 60 is accommodated is referred to as a second space 36.

The first partition plate 30 is provided to extend in a verticaldirection of a paper surface of FIG. 3. In other words, the firstpartition plate 30 partitions the internal space of the housing 70 intoa right space and a left space on the paper surface. An upper end partof the first partition plate 30 on the paper surface in FIG. 3 abuts onthe top panel 71, and a lower end part of the first partition plate 30on the paper surface in FIG. 3 abuts on the second partition plate 31.

The second partition plate 31 is provided to extend in a right-leftdirection on the paper surface in FIG. 3. In other words, the secondpartition plate 31 partitions the internal space of the housing 70 intoan upper space and a lower space on the paper surface. A right end partof the second partition plate 31 on the paper surface abuts on the firstpartition plate 30, and a left end part of the second partition plate 31on the paper surface abuts on an unillustrated side panel. The secondpartition plate 31 may also be used as a drain pan provided at aposition lower than is the second heat exchanger 5 or may be providedseparately from the drain pan.

The second air-sending device 7 is installed in the lower space in FIG.3 partitioned by the second partition plate 31. Further, a motor 7 athat drives the second air-sending device 7 and a shaft 7 b thattransmits rotation of the motor 7 a to the second air-sending device 7are installed together.

Further, a side surface part 5 a of the second heat exchanger 5 includesa metal part to cover a side surface of the second heat exchanger 5.

A drain cover 33 is provided between the front surface and therefrigerant pipe 15. The drain cover 33 is used as a passage compartmentthat guides moisture generated by the heat exchange in the refrigerantpipe 15 and the second heat exchanger 5, to the drain pan that isdisposed at a position lower than is the second heat exchanger 5.

The refrigerant flows through the refrigerant pipe 15. Depending on theoperation condition, the refrigerant is in the liquid phase state, thegas phase state, or the two-phase gas-liquid state. As illustrated inFIG. 3, the refrigerant pipe 15 accommodated in the housing 70 is oftendisposed to be located between the second heat exchanger 5 and thecontroller 60. The first partition plate 30 is disposed between therefrigerant pipe 15 and the controller 60. The first partition plate 30is configured to prevent spread of fire to the first space 35 when thecontroller 60 fires. Accordingly, an area toward the controller 60 fromthe refrigerant pipe 15 is in a plane state by the first partition plate30.

The side surface part 5 a of the second heat exchanger 5 is in a planestate by a metal part. Further, an area toward the front surface fromthe refrigerant pipe 15 is in a plane state by the drain cover 33. Anarea toward the rear surface from the refrigerant pipe 15 is also in aplane state as the rear surface of the housing 70 includes the base 76or the rear panel. In addition, an area toward an upper surface from therefrigerant pipe 15 is also in a plane state as the upper surfaceincludes the top panel 71.

In other words, the refrigerant pipe 15 accommodated in the housing 70is inevitably covered with the planes on front, back, left, right, top,and bottom. Accordingly, the first space 35 surrounding the refrigerantpipe 15 is a type of “chamber”. The first space 35, however, is unsealedand open. Therefore, the first space 35 can be defined as a “sound fieldspace” or a “sound field space”. In the following, the first space 35 isalso referred to as an “acoustic space”. The acoustic space isconsidered as a space in which well-known “standing waves” are presentin the vertical direction, the right-left direction, and the front-reardirection.

As the “standing waves” are present in the acoustic space, compressionalwaves are strengthened and weakened by amplification and attenuation atspecific frequencies that can be calculated from the “standing waves”present in the acoustic space in the first space 35. In other words, aphenomenon that is referred to as a resonance phenomenon occurs in thefirst space 35.

Further, in some cases, resonance corresponding to a dimension of thefirst space 35 occurs because of a columnar resonance phenomenon insidethe refrigerant pipe 15, and resonance sound in which a sound pressurelevel of a characteristic frequency component is increased is thuscaused in the first space 35.

The sound pressure level of the noise originally present in the firstspace 35 and, in some cases, the sound pressure level of the noisetransmitted to the outside of the refrigerant pipe 15 by the columnarresonance phenomenon are amplified by the resonance phenomenon in thefirst space 35. Further, the noise having the amplified sound pressurelevel is radiated from the first space 35 to the outside of the housing70. The noise becomes unpleasant noise that is released to a person. Inother words, the transmitted noise from the refrigerant pipe 15 and thenoise directly radiated from the first space 35 to the outside areessentially extremely small; however, the pressure levels of the noisesare amplified because of coincidence with the resonance frequency of thefirst space 35.

FIG. 5 is an explanatory diagram to explain “standing waves” present inan acoustic space. FIG. 6 is an explanatory diagram to explain “standingwaves in vertical direction” present in an acoustic space defined in ahousing of a common load side unit. FIG. 7 is an explanatory diagram toexplain “standing waves in front-rear direction” present in the acousticspace defined in the housing of the common load side unit. FIG. 8 is anexplanatory diagram to explain “standing waves in right-left direction”present in the acoustic space defined in the housing of the common loadside unit. The “standing waves” are described with reference to FIG. 5to FIG. 8. Note that a table illustrated in FIG. 5 is quoted fromSHIRAKI Kazuhiro, “Anti-noise design and simulation”, OhyogijyutsuPublication. Further, in FIG. 6 to FIG. 8, “X” is added at the end ofeach of reference signs of components corresponding to the components ofthe load side unit 100A, in distinction from the components of the loadside unit 100A.

A load side unit 100AX includes a housing 70X that forms an outer shell,as with the load side unit 100A. A front surface of the housing 70Xincludes a front panel 77X. Atop surface of the housing 70X includes atop panel 71X. A rear surface of the housing 70X includes a base 76X.Side surfaces of the housing 70X each include a side panel. A bottomsurface of the housing 70X includes a bottom panel 78X.

A wind direction adjusting unit 81X that adjusts a direction of airblown out from an air outlet 80X in vertical and right directions isdisposed at the air outlet 80X.

As with the housing 70, an inside of the housing 70X is partitioned by afirst partition plate 30X and a second partition plate 31X. In theinternal space of the housing 70X partitioned by the first partitionplate 30X and the second partition plate 31X, a space in which a secondheat exchanger 5X, a LEV 50X, and a refrigerant pipe 15X areaccommodated is referred to as a first space 35X. Further, in theinternal space of the housing 70X partitioned by the first partitionplate 30X and the second partition plate 31X, a space in which acontroller 60X is accommodated is referred to as a second space 36X.

A second air-sending device 7X is installed in a lower space partitionedby the second partition plate 31. Further, a motor 7 aX that drives thesecond air-sending device 7X and a shaft 7 bX that transmits rotation ofthe motor 7 aX to the second air-sending device 7X are installedtogether.

Further, a side surface part 5 aX of the second heat exchanger 5Xincludes a metal part to cover a side surface of the second heatexchanger 5X.

Furthermore, a drain cover 33X is provided between the front surface andthe refrigerant pipe 15X.

The “standing waves” are generated in a case where surfaces facing eachother are present in a space referred to as an acoustic space. It isfound from FIG. 5 that the standing waves are present and the resonancephenomenon occurs in any of three conditions where both ends are closed,the both ends are opened, and one of the ends is closed and the otherend is opened.

Taking measures against the resonance phenomenon reduces sound pressureamplification by the resonance in the sound field space, and it is thuspossible to prevent the noise from radiating to outside of a product.

The front and rear surfaces of the housing 70X of the load side unit100AX are formed by structure surfaces each made of a resin or othersimilar material, having relatively large thickness. More specifically,the front surface of the housing includes the drain cover 33X, and therear surface of the housing includes the base 76X or a rear panel.Therefore, it is possible to prevent the noise from transmitting to theoutside of the housing 70X. However, transitional noise other than therefrigerant noise, for example, stick-slip noise that is anabnormal-noise component generated between contacting parts may betransmitted as leakage noise to the outside of the housing 70X.

As illustrated in FIG. 6, the “standing waves in vertical direction”that are compressional waves are present in the first space 35X definedin the housing 70X of the load side unit 100AX (arrow A1). The “standingwaves in vertical direction” are dense in the vicinities of the toppanel 71X and the second partition plate 31X, and the sound pressure isamplified. Further, the “standing waves in vertical direction” aresparse at an intermediate part in the vertical direction of the firstspace 35X, and the sound pressure is attenuated. Accordingly, the soundpressure of the refrigerant noise is amplified in the vicinities of thetop panel 71X of the housing 70X and the second partition plate 31X, andthe refrigerant noise is transmitted to the outside of the housing 70X.

Further, as illustrated in FIG. 7, the “standing waves in front-reardirection” that are compressional waves are present in the first space35X defined in the housing 70X of the load side unit 100AX (arrow A2).The “standing waves in front-rear direction” are dense in the vicinitiesof the front panel 77X and the base 76X, and the sound pressure isamplified. Further, the “standing waves in front-rear direction” aresparse at an intermediate part in the front-rear direction of the firstspace 35X, and the sound pressure is attenuated. As described above,however, the transmission of the noise to the outside of the housing 70Xthrough the front surface and the rear surface of the housing 70X can beprevented. As the front panel 77X is openable, however, possibility thatthe noise is transmitted to the outside of the housing 70X cannot bedenied.

Moreover, as illustrated in FIG. 8, the “standing waves in right-leftdirection” that are compressional waves are present in the first space35X defined in the housing 70X of the load side unit 100AX (arrow A3).The “standing waves in right-left and vertical directions” are dense inthe vicinities of the side surface part 5 aX of the second heatexchanger 5X and the first partition plate 30X, and the sound pressureis amplified. Further, the “standing waves in right-left direction” aresparse at an intermediate part in the right-left direction of the firstspace 35X, and the sound pressure is attenuated. Accordingly, the soundpressure of the refrigerant noise is amplified in the vicinities of theside surface part 5 aX of the second heat exchanger 5X and the firstpartition plate 30X in the housing 70X, and the refrigerant noise istransmitted to the outside of the housing 70X.

As measures, in the load side unit 100A, a sound absorber is attached toat least one of the surfaces facing each other in the vertical directionin the sound field space and to at least one of the surfaces facing eachother in the right-left direction in the acoustic space. Further, thesound absorber is attached to a part corresponding to an “antinode” ofthe noise at which the compressional waves of the noise are amplified,to attenuate the resonance phenomenon occurring in the first space 35,and the sound pressure amplification of the noise transmitted to theoutside from the refrigerant pipe 15 is thus reduced. As a result, areflection state and a propagation state of the noise in the first space35 as an acoustic space are changed, and it is thus possible to preventoccurrence of the sound resonance phenomenon.

FIG. 9 is a schematic cross-sectional view schematically illustrating aconfiguration example of the load side unit 100A that includes a soundabsorber 90 at an upper part of the first space 35, as viewed from aside. FIG. 10 is a schematic cross-sectional view schematicallyillustrating the configuration example of the load side unit 100A thatincludes a sound absorber 91 at a rear surface part of the first space35, as viewed from a side. FIG. 11 is a schematic configuration diagramschematically illustrating the configuration example of the load sideunit 100A that includes a sound absorber 92 at a side surface part ofthe first space 35, as viewed from a front. FIG. 12 is a schematicconfiguration diagram schematically illustrating a state where theconfiguration examples of FIG. 9 to FIG. 12 are combined. The measuresagainst the “standing waves” of the load side unit 100A are describedwith reference to FIG. 9 to FIG. 12.

FIG. 11 and FIG. 12 each illustrate an inside of the load side unit 100Awith the front panel 77 removed from the load side unit 100A. Further,FIG. 3 illustrates the state viewed through the drain cover 33 in such amanner that the LEV 50 and the refrigerant pipe 15 are visuallyrecognizable.

As illustrated in FIG. 9, it is possible to take the measures againstthe standing waves generated between the top panel 71 and the secondpartition plate 31 by disposing the sound absorber 90 at the upper partof the first space 35, namely, at a part of a lower surface of the toppanel 71. In other words, the sound absorber 90 is disposed on the lowersurface of the top panel 71 that corresponds to the “antinode” of thenoise at which the compressional waves of the noise are amplified. As aresult, the sound absorber 90 can absorb the refrigerant noise radiatedto the first space 35 before the refrigerant noise repeats reflection inthe vertical direction. This noise absorbent makes it possible toprevent generation of the “standing waves in vertical direction” in thefirst space 35.

The case where the sound absorber 90 is disposed on the top panel 71 isdescribed as an example; however, the sound absorber 90 may be disposedon the second partition plate 31. Alternatively, the sound absorber 90may be disposed on each of the top panel 71 and the second partitionplate 31. In other words, attaching the sound absorber 90 on at leastone of the surfaces facing each other of the first space 35, namely, atleast one of the top panel 71 and the second partition plate 31 makes itpossible to prevent the resonance phenomenon in the first space 35.

Further, depending on the refrigerant condition, there is a case wherethe sound pressure is amplified inside the refrigerant pipe 15 by thecolumnar resonance of the refrigerant pipe 15, and the refrigerant noiseamplified inside the refrigerant pipe 15 is transmitted to the outsideof the refrigerant pipe 15, with the coincidence phenomenon. Asadditional measures, a sound absorber may be disposed at a positionwhere occurrence of the columnar resonance is anticipated, toeffectively attenuate the refrigerant noise. The position where theoccurrence of the columnar resonance is anticipated is determined by thepipe length of the refrigerant pipe 15.

Further, as illustrated in FIG. 10, it is possible to take the measuresagainst the standing waves generated between the drain cover 33 and thebase 76 by disposing the sound absorber 91 at the rear surface part ofthe first space 35, namely, at a part of the side surface of the base76. In other words, when the sound absorber 91 is disposed, the soundabsorber 91 can absorb the refrigerant noise radiated to the first space35 before the refrigerant noise repeats reflection in the front-reardirection. This noise absorbent makes it possible to prevent generationof the “standing waves in front-rear direction” in the first space 35.Further, disposing the sound absorber 91 can be used as the measuresagainst sudden noise.

The case where the sound absorber 91 is disposed on the base 76 isdescribed as an example; however, the sound absorber 90 may be disposedon the drain cover 33. Alternatively, the sound absorber 91 may bedisposed on each of the base 76 and the drain cover 33. In other words,attaching the sound absorber 91 on at least one of the surfaces facingeach other of the first space 35, namely, at least one of the base 76and the drain cover 33 makes it possible to prevent the resonancephenomenon in the first space 35.

Further, a sound absorber may be disposed at a position where occurrenceof the columnar resonance is anticipated, to effectively attenuate therefrigerant noise. The position where the occurrence of the columnarresonance is anticipated is determined by the pipe length of therefrigerant pipe 15.

Further, as illustrated in FIG. 11, it is possible to take the measuresagainst the standing waves generated between the side surface part 5 aof the second heat exchanger 5 and the first partition plate 30 bydisposing the sound absorber 92 at the side surface part of the firstspace 35, namely, at a part of the side surface of the first partitionplate 30. In other words, when the sound absorber 92 is disposed, thesound absorber 92 can absorb the refrigerant noise radiated to the firstspace 35 before the refrigerant noise repeats reflection in theright-left direction. This noise absorbent makes it possible to preventgeneration of the “standing waves in right-left direction” in the firstspace 35.

The case where the sound absorber 92 is disposed on the first partitionplate 30 is described as an example; however, the sound absorber 92 maybe disposed on the side surface part 5 a of the second heat exchanger 5.Alternatively, the sound absorber 92 may be disposed on each of thefirst partition plate 30 and the side surface part 5 a of the secondheat exchanger 5. In other words, attaching the sound absorber 92 on atleast one of the surfaces facing each other of the first space 35,namely, at least one of the side surface part 5 a of the second heatexchanger 5 and the first partition plate 30 makes it possible toprevent the resonance phenomenon in the first space 35.

Further, a sound absorber may be disposed at a position where occurrenceof the columnar resonance is anticipated, to effectively attenuate therefrigerant noise. The position where the occurrence of the columnarresonance is anticipated is determined by the pipe length of therefrigerant pipe 15.

Further, as illustrated in FIG. 12, it is possible to take the measuresagainst the “standing waves” generated in the vertical direction, thefront-rear direction, and the right-left direction by disposing thesound absorber 90, the sound absorber 91, and the sound absorber 92.

<Sound Absorber 90, Sound Absorber 91, and Sound Absorber 92>

Here, the sound absorber 90, the sound absorber 91, and the soundabsorber 92 are described. The sound absorbers have been separatelydescribed as the sound absorber 90, the sound absorber 91, and the soundabsorber 92 that correspond to the disposed positions; however, thesound absorber 90 is described below as a representative example.

The sound absorber 90 includes air chambers, and converts frequencycomponents in the audible band into heat energy to consume the noisecomponents in the audible band. The sound absorber 90 is made of, forexample, pulp fibers as a base material. More specifically, the soundabsorber 90 can be made of, for example, bioplastic that is obtained bycompressing and molding the pulp fibers. Accordingly, as compared withsome sound absorber made of glass fibers or other similar material, arisk such as mesothelioma potentially caused by the fibers scatteredfrom the material is avoided.

In the pulp fibers, a plurality of air holes are provided to across-section of each of the fibers. The pulp fibers largely include theair chambers as compared with the other fibers, and achieve high soundabsorption coefficient. Further, water repellent property may beimparted to the surface of the sound absorber 90. As a result, the soundabsorber 90 hardly absorbs moisture generated in the refrigerant pipe15, and it is thus possible to prevent deterioration of the soundabsorbing property. Further, the sound absorber 90 may contain anantifungal material. This antifungal material makes it possible toprevent occurrence of molds or other fungi even when the sound absorber90 absorbs moisture.

A sound insulator containing a dielectric material that performs thermalconversion of vibration may be stacked on the sound absorber 90. Thesound insulator preferably consumes the acoustic energy that istransmitted from the inside to the outside of the refrigerant pipe 15 byperforming the thermal conversion of vibration. Such a sound insulatormakes it possible to effectively attenuate the frequency components, inparticular, in the ultrasonic band, which are higher than the frequencycomponents in the audible band. The sound insulator can be made bykneading the dielectric material such as carbon into a polyester resinor other similar material.

Further, for example, a material having piezoelectric property may bekneaded into the sound insulator. Such a sound insulator can performthermal conversion of friction heat. In other words, when the acousticenergy enters the sound insulator, the sound insulator consumes, byfrictional heat energy conversion, vibration energy at a molecular levelin the material derived from pressure variation of the air, and aneffect is thus achieved to the acoustic energy of the ultrasonic bandhaving the strong sound pressure level.

Note that the size, the shape, and the thickness of the sound absorber90 are not particularly limited, and are determined depending on thesize and the shape of the first space 35 in which the sound absorber 90is disposed. However, the thickness of the sound absorber 90 ispreferably lower than or equal to 20 mm.

Further, the sound insulator may be stacked on each of the soundabsorber 91 and the sound absorber 92, and may be stacked on a soundabsorber 96 described in the following modification.

Disposing the sound absorber 90, the sound absorber 91, and the soundabsorber 92 in the first space 35 makes it possible to take the measuresagainst the “standing waves” in the first space 35, which is the soundfield space. In other words, even when the noise transmitted from therefrigerant pipe 15 is present, the transmitted noise is absorbed by thesound absorber 90, the sound absorber 91, and the sound absorber 92. Asa result, the transmitted noise is not reflected by the surfacesdefining the first space 35, and the resonance phenomenon does not occurin the first space 35. Accordingly, the noise does not leak to theoutside of the housing 70.

Further, as the sound absorber 90, the sound absorber 91, and the soundabsorber 92 are disposed on the surfaces defining the first space 35, itis unnecessary to dispose a sound absorber to the drain and passagecompartments on which water from the refrigerant pipe 15 or other waterflows. Accordingly, molds generated by moisture have less influence, anddeterioration of the sound absorbers can be reduced. Further, asinfluence by the molds is small, it is possible to maintain the firstspace 35 sanitarily.

Further, it is unnecessary to attach a dedicated cover that covers thewhole of the refrigerant pipe 15 to enclose the noise inside thededicated cover, or to provide an additional part to prevent the noisefrom transmitting from the dedicated cover. In other words, with theconfiguration of the load side unit 100A, the number of parts as themeasures against noise can be reduced, and the measures against thenoise that leaks to the outside of the housing 70 can be achieved at lowcost.

<Modification>

FIG. 13 is a schematic layout diagram schematically illustrating alayout example of the refrigerant pipe 15 inside the housing 70 of theload side unit 100A. FIG. 14 is a schematic configuration diagramschematically illustrating a modification of the load side unit 100A.FIG. 15 is an explanatory diagram to explain action in a case where asound insulator 97 is stacked on the sound absorber 96 and the stackedbody is disposed on the refrigerant pipe 15. FIG. 16 is a schematiccross-sectional view schematically illustrating a cross-sectionalconfiguration in the case where the sound insulator 97 is stacked on thesound absorber 96 and the stacked body is disposed on the refrigerantpipe 15. The modification of the load side unit 100A is described withreference to FIG. 13 to FIG. 16.

As illustrated in FIG. 13, the refrigerant pipe 15 is accommodated inthe housing 70 and bent at a plurality of positions. Further, asillustrated in FIG. 13, an intermediate component 55 such as a straineris often disposed on the refrigerant pipe 15. Pressure is easily appliedto bent parts of the refrigerant pipe 15, the intermediate component 55,and other similar part, and sound amplification caused by pressureincrease easily occurs at such parts.

For such a reason, as illustrated in FIG. 14, at least one of theintermediate component 55 and the bent parts of the refrigerant pipe 15is covered with a sound absorber, and it is thus possible to attenuateunnecessary noise radiation. FIG. 14 illustrates a case where all of theintermediate component 55 and the bent parts of the refrigerant pipe 15are covered with sound absorbers 96 a to 96 i, as an example. Further,FIG. 14 also illustrates the sound absorber 90 and the sound absorber91. Furthermore, in a case where it is unnecessary to separatelydescribe the sound absorbers 96 a to 96 i, the sound absorbers 96 a to96 i are correctively referred to as sound absorbers 96.

The columnar resonance occurs also inside the refrigerant pipe 15. The“dense” part of the noise by the columnar resonance inside therefrigerant pipe 15 and the “coincidence phenomenon” that is atransmission phenomenon by the pipe material are brought together toenhance the sound pressure level at an optional position of therefrigerant pipe 15, and transmitted noise is accordingly generated. Forsuch a reason, as illustrated in FIG. 14, as the noise is amplified atthe intermediate component 55 provided in the middle of the refrigerantpipe 15, the bent parts of the refrigerant pipe, and other similar part,and the sound absorbers 96 are provided at such positions.

In a case where a sound insulator is stacked on each of the soundabsorbers 96, the sound absorbers 96 are provided at the installationobjective parts, and the sound insulator is provided on the outside ofeach of the sound absorbers 96 a to 96 i. In other words, as illustratedin FIG. 15 and FIG. 16, each of the sound absorbers 96 and correspondingsound insulator 97 are stacked to form two-layer structure. Thisconfiguration makes it possible to surely attenuate acoustic energycomponents transmitted to the outside of the refrigerant pipe 15. Thisconfiguration is used as the measures against all of the generatedrefrigerant flow noise, and it is thus possible to reduce annoyance ofan inhabitant caused by unpleasant noise.

Further, as illustrated in FIG. 16, the sound absorbers 96 and the soundinsulators 97 are disposed to cover the entire circumference of therefrigerant pipe 15. This configuration makes it possible to reducenoise radiation causing sound propagation to the outside from the entirecircumference of the refrigerant pipe 15. Note that it is unnecessary tobond the sound absorbers 96 to an outer peripheral surface of therefrigerant pipe 15, and a gap may be present between surfaces of thesound absorbers 96 that face the pipe and the outer peripheral surfaceof the refrigerant pipe 15. The gap makes it possible to further improvethe sound absorbing effect. Further, even in a case where the soundinsulators 97 are not provided, the sound absorbers 96 are preferablydisposed to cover the entire circumference of the refrigerant pipe 15.

Note that, in the gas-phase state, passing noise when the refrigerantpasses through an extremely narrow space such as the LEV 50 is basicallygenerated. The components in the ultrasonic band are hardly generated inany of the phases, and the components in the audible band are mainlygenerated. Further, the generated noise includes sliding noise betweenthe refrigerant pipe 15 and the refrigerant. The sliding noise containsvibration components. Therefore, it is not possible to reduce thefrequency components transmitted from the refrigerant pipe 15 andpropagating to the outside of the refrigerant pipe 15 only by thevibration measures. It is necessary for the noise that has oncetransmitted through the refrigerant pipe 15 to the outside to besubjected to any outside processing for energy conversion processing. Toeffectively perform the thermal conversion, a noise radiation source ispreferably covered with a material including air chambers. Therefore,the periphery of the refrigerant pipe 15 directly connected to the LEV50 is preferably covered with a combination of the sound absorber andthe sound insulator to effectively reduce the noise radiation.

As described above, the unit for a refrigeration cycle device accordingto one embodiment of the present disclosure includes the housing 70 thatinternally includes the sound field space surrounded by the surfacesreflecting the sound waves, the LEV 50 that is disposed in the soundfield space, and the sound absorber provided on at least a part of thesurfaces defining the sound field space. Therefore, with theconfiguration of the load side unit 100A, it is possible to effectivelyattenuate the amplified noise generated in the sound field space only byproviding the sound absorber on the surface of the first space 35, whichis the sound field space.

Note that the sound absorber is at least one of the sound absorber 90,the sound absorber 91, and the sound absorber 92.

Therefore, in the unit for a refrigeration cycle device according to oneembodiment of the present disclosure, the noise measures by theeffective sound field control are achievable only by specifying thelocations of the sound absorbers each made of few materials. Further, inthe unit for a refrigeration cycle device according to one embodiment ofthe present disclosure, it is unnecessary to cover the whole of therefrigerant pipe 15 with a damping material, and it is thus possible toreduce labor and cost for the damping material. Furthermore, in the unitfor a refrigeration cycle device according to one embodiment of thepresent disclosure, as it is unnecessary to dispose the sound absorberto the drain and passage compartments on which water from therefrigerant pipe 15 and other water flows, molds generated by moisturehave less influence, and deterioration of the sound absorbers can bereduced.

In the unit for a refrigeration cycle device according to one embodimentof the present disclosure, the expansion device is the LEV 50.Therefore, it is possible to take the measures against the transmittednoise that is transmitted from the inside to the outside of therefrigerant pipe 15 connected to the LEV 50.

In the unit for a refrigeration cycle device according to one embodimentof the present disclosure, the sound absorber is made of the pulp fibersincluding air chambers. Therefore, it is possible to take the measuresagainst both of the transmitted noise of the audible band and thetransmitted noise of the ultrasonic band, and a risk such asmesothelioma potentially caused by the fibers scattered from thematerial is avoided.

Note that the sound absorber is at least one of the sound absorber 90,the sound absorber 91, and the sound absorber 92.

In the unit for a refrigeration cycle device according to one embodimentof the present disclosure, the sound absorbers 96 are further providedat the bent parts of the refrigerant pipe 15 and the intermediatecomponent 55. Therefore, it is possible to attenuate the unnecessarynoise radiation at positions where sound amplification by pressureincrease easily occurs.

In the unit for a refrigeration cycle device according to one embodimentof the present disclosure, the sound insulator 97 containing thedielectric material is stacked on the sound absorber. Therefore, it ispossible to surely attenuate the acoustic energy components transmittedto the outside of the refrigerant pipe 15. Accordingly, in the unit fora refrigeration cycle device according to one embodiment of the presentdisclosure, it is possible to take the measures against all of thegenerated refrigerant flow noise, and to reduce annoyance of aninhabitant caused by unpleasant noise.

Note that the sound absorber is at least one of the sound absorber 90,the sound absorber 91, the sound absorber 92, and the sound absorbers96.

The refrigeration cycle device according to one embodiment of thepresent disclosure includes the above-described unit for a refrigerationcycle device. Therefore, it is possible to effectively attenuate theamplified noise generated in the sound field space of the unit for arefrigeration cycle device.

As one of the units for a refrigeration cycle device according to oneembodiment of the present disclosure, the load side unit 100A has beendescribed as a representative example. The described contents aresimilarly applicable to the heat source side unit 100B. Therefore, whenthe refrigeration cycle device according to one embodiment of thepresent disclosure includes the heat source side unit 100B that issubjected to the noise measures described for the load side unit 100A,it is possible to effectively attenuate amplified noise generated in asound field space of the heat source side unit 100B.

The electric apparatus according to one embodiment of the presentdisclosure includes the above-described refrigeration cycle device.Therefore, it is possible to take the measures against unpleasant noisegenerated from an electric apparatus familiar to an inhabitant, and toreduce annoyance of the inhabitant.

Examples of the electric apparatus include an air-conditioningapparatus, a water heater, a freezer, a dehumidifier, and arefrigerator.

REFERENCE SIGNS LIST

1 compressor 2 flow switching device 3 first heat exchanger 5 secondheat exchanger 5X second heat exchanger 5 a side surface part 5 aX sidesurface part 6 first air-sending device 7 second air-sending device 7Xsecond air-sending device 7 a motor 7 aX motor 7 b shaft 7 bX shaft 15refrigerant pipe 15X refrigerant pipe 30 first partition plate 30X firstpartition plate 31 second partition plate 31X second partition plate 33drain cover 33X drain cover 35 first space 35X first space 36 secondspace 36X second space 55 intermediate component 60 controller 60Xcontroller 70 housing 70X housing 71 top panel 71X top panel 71 aopening port 76 base 76X base 77 front panel 77X front panel 78 bottompanel 78X bottom panel 80 air outlet 80X air outlet 81 wind directionadjusting unit 81X wind direction adjusting unit 90 sound absorber 91sound absorber 92 sound absorber 96 sound absorber 96 a sound absorber96 b sound absorber 96 c sound absorber 96 d sound absorber 96 e soundabsorber 96 f sound absorber 96 g sound absorber 96 h sound absorber 96i sound absorber 97 sound insulator 100 refrigeration cycle device 100Aload side unit 100AX load side unit 100B heat source side unit

1. A unit for a refrigeration cycle device, the unit comprising: ahousing that has a plurality of surfaces and internally includes a soundfield space surrounded by the plurality of surfaces, the plurality ofsurfaces each reflecting sound waves; an expansion device disposed inthe sound field space and configured to adjust a flow rate ofrefrigerant; a refrigerant pipe disposed in the sound field space andconnected to the expansion device; and a sound absorber disposed on,among the plurality of surfaces, one or both of two surfaces that faceeach other in the sound field space.
 2. The unit for a refrigerationcycle device of claim 1, wherein the expansion device is an electronicexpansion valve.
 3. The unit for a refrigeration cycle device of claim1, wherein the sound absorber is made of pulp fibers including airchambers.
 4. The unit for a refrigeration cycle device of claim 1,wherein the sound absorber is further provided to a bent part of therefrigerant pipe and an intermediate component provided to therefrigerant pipe.
 5. The unit for a refrigeration cycle device of claim1, wherein a sound insulator containing a dielectric material is stackedon the sound absorber.
 6. A refrigeration cycle device, comprising theunit for a refrigeration cycle device of claim 1, as at least one of aheat source side unit and a load side unit.
 7. An electric apparatus,comprising the refrigeration cycle device of claim 6.